16 



THE ORTHOPTERA OF MINNESOTA. 



To the casual observer, the eggs of our locust appear to 

 be thrust indiscriminately into the hole made for their recep- 

 tion. A more careful study of the egg-mass, or egg-pod, 

 will show, however, that the female took great pains to ar- 

 range them, not only so as to economize as much space as 

 possible, consistent with the form of each egg, but so as to 

 best facilitate the escape of tlie young locust; for if, from 

 whatever cause, the upper eggs should fail to hatch, or 

 should hatch later than the lower ones, the former would 

 offer an impediment to the exit of the young in their en- 

 deavor to escape from these last, were there no provision 

 against such a possibility. The eggs are, indeed, most care- 

 fully placed side by side in four rows, each row containing 

 seven. They oblique a little cross-wise of the cylinder (Fig. 

 4, a). The posterior or narrow end, which issues first from 



the oviduct, is thick- 

 ened, and generally 

 shows two pale 

 rings around the 

 darker tip(Fig. 4, b). 

 This is pushed close 

 against the bottom 



Fig. 4.— Egg-mass of Rocky Mountain Locust— of the burrOW, 

 a, from the side, within burrow; b, (rom beneath; 



c, from above; enlarged. (After Riley). W^hich, bciug Cylin- 



drical, does not permit the outer or two side rows to be 

 pushed quite as far down as the two inner rows, and for 

 the very same reason the upper or head ends of the outer 

 rows are necsesarily bent to the same extent over the 

 inner rows, the eggs when laid being somewhat soft 

 and plastic. There is consequently an irregular channel 

 along the top of the mass (Fig. 4, c.) which is filled only with 

 the same frothy matter that surroundseach egg, which mat- 

 ter occupies all the other space in the burrow not occupied 

 by the eggs. The whole plan is seen at once by a reference 

 to the accompanying figure, which represents, enlarged, a 

 side view of the mass within the burrow (a) and a bottom 



